I see different things used on 2nd Gen RX7's from different years that were not options each year(EX. Something from the 1989 engine and body wing). I also see BMW built from 1992 Chasis, but ad Vanos motor even though it was not available. Why can you not make a 1990 miata into a 1.8 1994 miata. The body is the same. I understand the brakes are different too. Just confused due to the BMW and RX7 combo's out there.

Greg